One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,6)(4,5)(7,8)(9,10)(11,13)(12,14)(15,16)(17,18)(19,23)(20,28)(21,25)(22,26)(24,31)(27,30)(29,32) involution — undirected(2,5)(6,8)(9,11,12,15)(10,13,14,16)(17,19,22,25)(18,21,26,23)(20,27,30,28)(24,29,32,31)(17,20,21,29,22,30,23,31)(18,24,19,27,26,32,25,28)(10,14)(13,16)(17,18)(19,21)(20,24)(22,26)(23,25)(27,29)(28,31)(30,32) involution — undirected(1,3,4,7)(2,6,5,8)(17,21,22,23)(18,25,26,19)(20,29,30,31)(24,28,32,27)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.